Temperature measuring device



Feb. 8, 1938. l. L. CANUTE SON TEMPERATURE MEASURING DEVICE 2 Sheets-Sheet 2 Fild April 29, 19:57

IllllllllllllllllllllllililllllllllllllliiiiiiillllI Patented F ch. 8, 1938 Nl'i'ED STATES PATENT OFFICE TEMPERATURE MEASURING DEVICE Application April 29, 1937, Serial No. 139,808

11 Claims.

This invention relates to a device, termed a temperature thief, for measuring the temperature of oils and other liquids. Devices of this type consist in general of an open bowl having a thermometer associated therewith adapted to be lowered into a tank of liquid and including means for closing the bowl to entrap a sample of the liquid and for raising the bowl to the surface to obtain a temperature reading. By taking samples of the liquid at various points and at difierent elevations throughout the tank it is possible to obtain its mean temperature from which to compute the normal volume of the liquid in the tank at some designated basic temperature, and, by

analysis, to determine the average composition or quality of the liquid.

I In devices of the above character, it is necessary that the bowl be of simple and sturdy construction, easy to manipulate and positive in operation. To obviate false temperature readings that enter cumulatively into the final volumetric determination it is of the utmost importance that the bowl be absolutely fluid-tight after closing to avoid contamination of the entrapped sample by the surrounding body of liquid through which it is raised and to prevent evaporation of the sample after the bowl has been removed from the tank for the purpose of reading the thermometer.

It is an object of my invention to provide a temperature thief incorporating the abovementioned advantages, which includes a bowl spring-supported upon a suspension rod carrying a valve disk adapted to close an inlet in the bottom of the bowl under the urge of the spring and also including a latch for retaining the bowl against the pressure of the spring but releasable upon a jerk of the suspension rod to raise the bowl into closed position with the valve and entrap a sample of liquid therein.

A further object of my invention is to provide in a temperature thief of the above character a latching mechanism for retaining the bowl and suspension rod in relatively displaced position with the spring under compression and including a detent transversely slidable upon one of said members and engaging a ledge upon the other member and retained against disengagement solely by the frictional contact resulting from the pressure exerted by the spring. By this arrangement, when a jerk is imparted to the suspension rod transmitted by the operator through the cord by which the device is lowered into the tank of liquid, the spring is momentarily further compressed to relieve the frictional contact between 5 the detent and ledge and to cause means to become operative to slide the detent out of latching engagement with the ledge. Preferably I provide a spring member to slide the detent when the latch is released, but a cam, or both a cam and a spring, may be provided for this purpose.

In the preferred form of my invention the bowl is provided with a second inlet opening in its top and includes a floating valve which is adapted to be supported above its inlet when the apparatus is latched open but which seats by gravity 10 and closes this inlet when the latch is released. By reason of the virtually independent operation of the valves, one valve cannot interfere with the tight seating of the other valve such as is likely to occur, due to expansion, in certain types of 5 temperature measuring devices in which the valves are rigidly connected for unitary operation.

Other objects and advantages will be apparent from the following detailed description of a 20 preferred embodiment of the invention, reference being had to the annexed drawings in which:

Figure l is a vertical cross-sectional view through a temperature measuring device of the type used in obtaining the temperature of oils, 25 the valves being shown in full lines in open position and in dotted lines in closed position;

Figure 2 is a view in side elevation of the temperature measuring device of Fig. 1;

Figure 3 is a view in cross-section on the line 3-3 of Fig. 1 through the rod forming an armor for the thermometer tube;

Figure 4 is a cross-sectional view through the latching mechanism on the line 44 of Fig. 1;

Figure 5 is a cross-sectional view through the 35 cage surrounding the thermometer well on the line 55 of Fig. 1; and

Figure 6 is a modified form of latching mechanism and showing the latch in sprung or released position.

The temperature thief illustrated in the drawings comprises a generally cylindrical bowl i and a hollow suspension rod 2 extending axially upwardly therefrom through the top of the bowl. Within the rod 2 is housed a thermometer tube 3, 45 the rod providing an armor for the tube and having a window 4 of magnifying glass extending throughout a substantial portion of its length to permit inspection of the thermometer which is calibrated in the usual manner, for example, 50 from 0 to 180 F. The rod 2 is closed by a cap 5 screwed into its upper end and this plug is formed with transverse finger lugs to and an eye 6 for the attachment of a suspension cord for lowering the device into a tank of liquid and for closing its inlets in a manner which later will be described. To the lower end of the rod 2 and constituting a prolongation of the suspension rod is threadedly secured, as at 1, a hollow valve rod 2a. transversely recessed throughout the major portion of its length (see Fig. 5) and serving as a cage for the Well end 3a of the thermometer tube 3.

The bottom of the valve rod is formed as a valve disk Hi having a tapered periphery from which depend a plurality of guide fingers lilo.

This valve serves to close an inlet opening II 'in' the bottom of a cupl2 constituting a detachable nose piece threaded upon the lower end of the bowl l and forming a part thereof. inlet H where it opens into the container is circumferentially tapered to present a seat Ha for the complementary tapered valve disk it. A liner to of bakelite or other thermally nonco-nductive material extends into and overlies the inner circumference of the bowl I to retard the transmission of heat through the walls of the bowl.

This bowl is sup-ported at its top by a spider i4 comprising four radical arms Ma extending outwardly from a central cylindrical hub l5 and secured'by a tongue-and-slot fit to arms H projecting upwardly from the rim of the bowl. A screw i6 retains the spider and arms against relative shifting movement. The hub is formed with an oversize axial bore to receive the sus pension rod, the clearance space surrounding the latter providing a spring chamber I 8. The upper end of this spring chamber is closed by an inwardly directed flange I8a snugly but slidably surrounding the end of the rod 2. Within chamber I8 is a coil spring 19 surrounding the lower end of the rod 2 and bearing at one end against an enlarged terminal lip 2t upon the end of the rod and at its other end against the flange Ida. The circumference of lip 20 is such as to slidably fit within the bore of chamber l8. By drawing the suspension rod upwardly the coil spring is is compressed and exerts a thrust between the suspension rod and the bowl tending to move the valve seat Ha into engagement with the valve disk ID, as shown by the broken lines 1933.

In order to retain the device in set condition a latch pin 2| extends radially through an opening 22 in the flange Isa. This opening is, expanded upon the inner circumference of the flange to form an enlarged pocket 22a which slidably receives a detent 23 carried upon the end of the latch p-irr 2|. To the detent 23 is fastened one end of a semi-circular wire 24 of spring steel loosely received in a circumferential groove 25 in the flange IBa, as indicated in. Fig. 4. The opposite end of the wire spring is provided with an offset portion 24a which is anchored inthe wall of groove 25. A groove 250. formed in the circumference of rod 2 near its lower end provides a ledge designed to be en.-

gaged by the detent 23. The arrangement is such that after the bowl and suspension rod have been displaced against the action of coil spring l9 so as to bring detent 23 in the plane with groove 25a, the latch pin 2| may be pushed inwardly by means of the knurled finger piece Zla against the pressure of the wire spring 24. The pressure exerted by coil spring l9 will cause the detent 23 to bear against the ledge of groove 25a with such pressure as to frictionally maintain the detent in engagement with the ledge in opposition to the pressure exerted by wire spring its seat Ma.

The

2d. When engagement between the detent 23 and groove 25a is momentarily relieved by a sudden jerk imparted to the suspension rod 2, which further compresses coil spring E9, the wire spring acts to slide the detent to the left (Fig. l) to release the latch. Coil spring l9 then snaps bowl 5 sharply upward until the valve disk Ill engages Inorder to positively insure the disengagement of the detent from its groove when the latch is operated, the lower wall of the groove 25a is inclined downwardly and outwardly to present a cam surface 30 which cooperates with a companion inclined face 38 on the detent 23 so that when the rod 2 is jerked upwardly the cam surfaces cooperate to slide the detent in the same direction as that in which a thrust is exerted by the wire spring 24.

Below the lower end of hub i5 is provided a floating valve disk 33 centrally recessed to snugly but slidably encircle a'reduced circumferential portion 34 of the valve rod 2a adjacent its upper end. This valve is allowed limited vertical movement along the reduced circumferential portion and is supported by a shoulder 35 upon the latter when the latch 2! is engaged. The outer circumference of the floating valve is taperedso that upon release of the latch and movement of the bowl upwardly this tapered edge comes to rest upon the tapered seat 35a of an inlet 36 formed in the top of the bowl, and the valve closes this inlet by its own weight as shown by broken lines 33x. Since the two valves iii and 33 are not rigidly connected and operate, in a sense, independently of each other it will be apparent that any variation inthe length of the suspension rod, constituting parts 2 and 2a with which the valves are associated, will not interfere with the tight closing of either valve.

The manner of associating the thermometer with the rod 2 and valve rod 2a is best illustrated in Figs. 1 and 2. As shown in these figures, the thermometer tube 3 is provided with a tightly fitting fibrous collar 3'! somewhat above its well portion, which, after slipping the thermometer tube upwardly within the rod 2, seats within an enlarged recess 38 in the upper end of rod. 2a with the lower portion of the thermometer tube extending axially downward through a bore 39 into the cage 9. A closure at is screwed over the end of valve rod 2a and has an inturned flange 40a overlying the collar 3?. The cap 5 is recessed to receive the upper endof the thermometer tube when screwed onto the top of rod 2. When the apparatus is assembled, the rod 2 will be screwed tightly down against the upper face of the closure 42 so as to make fluid-tight seal therewith.

In the operation of thetemperature thief described above, the apparatus is latched by holding the bowl in the left hand with the index finger pressing against the finger piece 2 la of the latch and tending to force detent 23 inwardly. With two fingers of the right hand under the lugs 5a of cap 5 the suspension rod is pulled upwardly with a spiral motion, compressing coil spring l9 until circumferential groove 25a in rod 2 arrives opposite the detent 23. Thereupon the detent is forced into the groove against the action of wire spring 24 and engages a ledge of the groove to'latch the bowl open with the valves l0 and 33 shown) attached to the eye 5 at the top of the suspension rod 2, 2a. Since the inlets in the bottom and top of the bowl are open, this permits the rapid lowering of the bowl. The cord is then given a sharp jerk causing the suspension rod to momentarily rise against the pressure of already compressed coil spring It! so that the ledge of groove 25a is lifted out of contact with detent 23 which permits wire spring 24 to become effective to slide the detent out of latching engagement with the groove. This causes coil spring I 9 to move the bowl upwardly so as to bring valve seat I la surrounding the bottom inlet II into engagement with valve Ill, and to bring valve seat 36a of the inlet 36 in the top of the bowl into engagement with floating valve 33 as indicated by the broken lines His: and 33a: in Fig. 1. The bowl containing the entrapped sample of liquid may then be raised to the surface and the thermometer 3 consulted to ascertain the temperature of the sample.

In Fig. 6 is illustrated a modified form of latching mechanism differing from that just described principally in the provision of a coil spring 4| surrounding the latch pin 2| in place of the wire spring 24 shown in Fig. 4. This spring is relatively weak but has sufiicient bias to slide the detent out of operative engagement with the groove 25a when frictional contact between the detent and groove is broken by an, upward jerk of the suspension rod. In order to render the device more sensitive to jerks imparted to the suspension rod, the detent is formed with a conical head 42 which makes edge contact with the ledge presented by the groove. A collar 43 upon the latch pin 2i provides a stop for limiting the outward movement of the detent in its pocket 22a.

The device being open at its top and bottom creates a washing effect through the bowl while being lowered and for this reason the time in which the device will reach equilibrium with the oil is considerably shortened. If it is desired, for greater accuracy, to fill, empty and refill the device with the tank liquid before taking a temperature reading so as to equalize the temperature of the parts of the device with that of the liquid, this may bereadily accomplished since to empty the device it is only necessary to raise the device slightly above the level of the liquid in the tank and momentarily lift the valve assembly against the action of spring l9.

After the latch has been tripped the valves are held tightly closed. In the case of valve Hi, this valve is retained closed by the spring l9 supplemented by the Weight of the entrapped sample, while in the case of valve disk 33 by atmospheric pressure and the weight of the valve disk itself. A more trustworthy temperature reading is obtained because of the relatively large volume of liquid contained in the bowl and insulating the thermometer from atmospheric temperatures when the bowl is withdrawn from the tank; and also because of the prevention of cooling by evaporation which, particularly in the case of the more volatile hydrocarbon oils, is a common source of error in determining the mean temperatures of tank liquids. I prefer to make the bowl of my device of chromium-plated bronze as I have found that this material conduces to more accurate readings than in the case of copper or brass.

It will be apparent that my invention may be embodied in other forms than that shown and described herein, and that various changes in structure and design may be made from the example herein disclosed without departing from the spirit of my invention.

I claim:

1. A temperature measuring device comprising a bowl having inlets at opposite ends, a suspension rod extending axially through the top of the bowl, a thermometer mounted upon the suspension rod with its lower end extending into the bowl, a coil spring surrounding the suspension rod and yieldingly supporting the bowl, valves carried by the suspension rod for closing the inlets and a latch for retaining the bowl and suspension rod in displaced relation in opposition to the spring, said latch comprising a slidable detent carried by the bowl and engaging a ledge upon the suspension rod, and biasing means operable upon further longitudinal displacement of the bowl and suspension rod to slide said detent to inoperative position.

2. A temperature measuring device comprising a bowl having inlets at opposite ends, a suspension rod extending axially through the top of the bowl, a thermometer mounted upon the suspension rod with its lower end extending into the bowl, a coil spring surrounding the suspension rod and yieldingly supporting the bowl, valves carried by the suspension rod for closing the inlets and a latch for retaining the bowl and suspension rod in displaced relation in opposition to the spring, said latch comprising a slidable detent carried by the bowl and engaging a ledge upon the suspension rod, and cam means operable upon further longitudinal displacement of the bowl and suspension rod to slide said detent to inoperative position.

3. A temperature measuring device comprising a bowl having an inlet in its bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end disposed within the bowl, a valve upon the suspension rod adapted to close the inlet in the bottom of the bowl, a spring tending to move the bowl relative to the suspension rod and retain the inlet closed by the valve, and a latch for retaining the bowl and suspension rod displaced against the action of the spring with the valve separated from the inlet, said latch comprising a detent supported by the bowl and slidable to operatively engage a ledge upon the suspension rod, said detent being responsive to a jerk upon the suspension rod to release its engagement with the ledge and means for sliding said detent into inoperative position to permit said bowl to rise and close the inlet against the valve.

4. A temperature measuring device comprising a bowl having an inlet in its bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end disposed within the bowl, a valve upon the suspension rod adapted to close the inlet in the bottom of the bowl, a spring tending to move the bowl relative to the suspension rod and retain the inlet closed by the valve, and a latch for retaining the bowl and suspension rod displaced against the action of the spring with the valve separated from the inlet, said latch including a detent supported by the bowl and being slidable to operatively engage a ledge upon the suspension rod, and resilient means tending to slide the detent into inoperative position upon disengagement of the detent with the ledge by a jerk of the suspension rod to permit the bowl to rise and close the inlet.

5. A temperature measuring device comprising llllllllllllllll a bowl having an inlet in its bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end disposed within the bowl, a valve upon the suspension rod'adapted to close the inlet in the bottom of the bowl, a spring tending to move the bowl relative to the suspension rod and retain the inlet closed by the valve, and a latch for retaining the bowl and suspension rod displaced against the action of the spring with the valve separated from the inlet, said latch including a detent supported by the bowl and engaging a ledge upon the suspension .rod, detent being retained in engagement 1 the ledge by the pressure of the spring, and mes s for sliding the detent into inoperative position upon disengagement of the detent with the ledge by a jerk of the suspension rod to permit the bowl to rise and close the inlet.

6. A temperature measuring device comprising a bowl having an inlet in its bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end disposed within the bowl, a valve upon the suspension rod adapted to close the inlet in the bottom of the bowl, a spring tending to move the bowl relative to the suspension rod and retain the inlet closed by the valve, and a latchior retaining the bowl and suspension rod displaced against the action of the spring with the valve separated from the inlet, said latch including a detent slidable to operatively engage a ledge upon the suspension rod and being retained in engagement with the ledge solely by frictional pressure exerted by the spring and resilient means for sliding thedetent into inoperative position upon disengagement of the detent with the ledge by a jerk of the suspension rod to permit the bowl to rise and close the inlet. '7. A. temperature measuring device comprising a bowl having inlets in its top and bottom, a suspension rod projecting axially upwardthrough top of the bowl, a thermometer associated with the suspension rod with its lower end disposed witliin the'bowl, a valve upon the suspension rod adapted to close the inlet in one end of the bowl, a spring exerting pressure between the bowl and suspension rod and tending to retain said inlet closed by the valve, a second valve encircling said suspension rod and designed to close the inlet at the opposite end of the bowl by its own weight, a latch for retaining the bowl and suspension rod relatively displaced against the action oi the spring with the first-mentioned valve separated from its inlet, means associated with the suspension rod for supporting the second-mentioned valve away'from its inlet when the latch is engaged, and means responsive to a jerk upon the suspension rod for releasing the latch to permit the closing of the inlets by the valves.

8. A temperature measuring device comprising a bowl having inlets in its top and bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end disposedwithin the bowl, a valve upon the suspension rod adapted to close the inlet in the bottom of the bowl, a spring exerting pressure between the bowl and suspension rod and tending to retain said inlet closed by the valve, a second valve encircling said suspension rod and designed to close the inlet in the top of the bowl by its own weight, a latch for retaining the bowl and suspension rod relatively displaced against the action of the spring with the first-mentioned valve separated from the bottom inlet, a stop carried by the suspension rod for supporting the secondmentioned valve away from the top inlet when the latch is engaged, and means responsive to a jerk upon the suspension rod for releasing the latch to permit closing of the bottom inletby the first-mentioned valve under spring pressure and closing of the top inlet by floating engagement of the second-mentioned valve therewith.

9, A temperature measuring device comprising a bowl having an inlet in its bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end disposed within the bowl, a valve upon the suspension rod adapted to close the inlet in the bottom of the bowl, a spring tending to move the bowl along the suspension rod and retain the inlet closed by the valve, and a latch for retaining the bowl and suspension rod displaced against the action of the spring with the valve separated from the inlet, said latch includingra detent supported by the bowl and engaging a ledge upon the suspension rod, means for shifting the detent out of engagement with the. ledge upon a jerk of the suspension rod and permit thebowl to rise and close the inlet, a floating valve slidahly associated with the suspension rod above the bowl and adapted to close an inlet in the top of the bowl, and a stop retaining the floating valve'out of engagement with the inlet in the top of the bowl when the bowl is latched in its lowered position, said floating valve upon release of the latch being designed toclose said last-mentioned inlet by its own weight.

10. A temperature measuring device comprising a bowl having inlets in its top and bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end ,disposed within the bowl, a valve disk fixed upon the lower end of the suspension rod adapted to close the inlet in the bottom of the bowl, and a floating valve disk loosely surrounding the suspension rod and seating by gravity upon the inlet in the top of the bowl, a spring exerting pressure between the bowl and suspension rod and normally tending to shift the bowl into closed position with the valve disks, and a latch for retaining bowl and suspension rod longitudinally displaced and for maintaining the inlets open against the action of the spring.

' 11. A temperature measuring device comprising a bowl having inlets in its top and bottom, a suspension rod projecting axially upward through the top of the bowl, a thermometer associated with the suspension rod with its lower end dis posed within the bowl, a valve disk fixed upon the lower end of the suspension rod adapted to close the inlet in the bottom of the bowl, and a floating valve disk loosely surrounding the. sus- I pension rod and seating by gravity upon the inlet in the top of the bowl, a spring exerting pressure between the bowl and suspension rod and normally tending to shift the bowl into closed position with the valve disks, a latch for retaining the bowl and suspension rod longitudinally displaced to maintain the inlets open against the action of the spring, and an abutment upon the suspension rod engaging the floating valve disk to retain said floating valve disk above its inlet when the bowl and suspension rod are displaced into latch engaging position.

' IRVING LORENZO CANUTESON 

